Machine to produce spiral grooves



Oct 1943- A. RICKENMANN 2,330,921

'MACHINE TO PRODUCE SPIRAL GROO VES Filed April 18, 1942 Patented Oct. 5, 1943 2,330,921 MACHINE TO PRODUCE SPIRAL GROOVES Alfred Rickenmann, Zurich, Switzerland; vested in the Alien Property Custodian Application April 18, 1942, Serial No. 439,511 In Switzerland December 13, 1940 9 Claims.

The invention relates to a new and improved machine to produce spiral grooves or teeth in cylindrical blanks for instance spiral gears.

The invention relates more particularly to machines of the said type which may be used to produce grooves or teeth with any helix angle and lead on blanks of any diameter.

The main object of the invention is the provi, sion of means to get a very high precision in shaping the grooves or teeth to the correct helix angle and lead by very simple means.

In the drawing I Fig. 1 is a side elevation of part of a machine shown in a diagrammatical manner.

Fig92 is a section taken on line II-II of Fig. 1.

Figs. 3 and 4 are sections on the lines III-III and IV -IV of Figs. 1 and 2.

On a base I a carriage 2 is slidably mounted on horizontal ways. In the base I there is arranged a cylinder 3 communicating with pipes 4 and 5 with a pressure fluid mechanism ofknown construction and not shown in the drawing. The pis-, ton 6 of the cylinder 3 is fastened to a bracket 1 of the carriage 2 the latter being reciprocated by the piston 6. On the carriage 2 the work-piece W is fastened to an arbor which is held between the points l3,- H. The point I4 is arranged on a support 8 and the point l34is attached to a shaft Ill. The shaft II) is 'ournalled in bearings ll of the carriage 2. A clamping device l2, [5 connects the work-piece W with said shaft I 0, for

rotation with the shaft III. A spur wheel l3 fixed to shaft drives by means of an inter mediate gear I! a spur wheel l8. The gear I8 is fixedly arranged on a shaft 2| which is supported in bearings I9, 20. Splines 23 on shaft 2| 'engage corresponding grooves in the bore of the bevel gear 22. The rotation of the latter is transmitted to said shaft 2| and through the gears I8, l1, to the work-piece W at any position of the carriage 2 on the base I. The bevel gear 22 is driven by a bevel gear 24 on shaft 25 journalled in the base" I A spur gear 26 fixed to shaft 25 is in engagement with gear 21 on an intermediate shaft 28 on which a gear 23 meshes with gear 30 on a shaft 3| arranged co-axially with shaft 25.- The intermediate shaft 28 is journalled in a frame 32 rotatably mounted on the two shafts 25 and-3|. An annular spur gear 33 fastened to the rotary frame 32 engages gear 34 of a set of gears 34, 35 on shaft 38. The gearing, furthermore, includes gears 36, 31 on shaft 39, and gear 40 keyed on shaft 4|. The latter is Journalled in the base I and carries a spur wheel 42 meshing with a rack 43, arranged on the car- "\rack 43 is slidably arranged in ways 44, running parallel to the direction of travel of the carriage 2. A stud 45 fixed to an arm 46 of an angular lever 41 enters an elongated slot of rack 43, the other'\ arm of the lever 41 carrying pivotally a block 48. The bell crank lever 41 turns on a pivot 49 fixed to carriage 2 and the block 48 slidingly engages a straight groove 50 of a correcting member 5|. The latter pivots about a stud 52 in a lateral extension of the base I, the main her 51 isprovided with a circular slot 53, and may be held in selected angular position by a clamping screw 54 passing through the slot 53. The angular position of the groove 50 with reference to the path of carriage 2 may be adjusted and read off on a scale 54 and an index 55. When the carriage 2 reciprocates, the rack 43 connectedwith the carriage through the elements 45, 46, 49

also reciprocates but an additional feed is given to the rack 43 due to the rocking movement of lever 46 induced by'the movement .of block 48 in groove 50 of the said correcting member 5|. To cut the grooves on the work-piece W a rotary tool 63 is arranged, for instance a milling cutter, a grinding disk and so on, which is positively driven by a motor not shown in the drawing. The shaft of the tool preferably is set at an angle with reference to the axis of the work-piece W corresponding to the lead or pitch of the spiral groove G to be cut. The lead of the groove G may be varied by choosing appropriate change speed gears Hi to 4|. Right handed grooves or left handed grooves may be produced by changing the direction of rotation of the work-piece W by inserting or removing a transmitting spur wheel in the train of the said gears as known per se.

To produce a groove G of a certain lead or with a certain helix angle, a set of predetermined change speed gears Hi to 4| is to be used. It frequently happens that change speed gears of the correct diameters are not available to get exactly the desired lead. The new machine allows to compensate any inaccuracy. The angular position of the groove 50-is selected according to requirement to impart the proper rotation to the work-piece at a given and constant stroke of the carriage 2.

The change speed gears necessary to produce a number of different leads may be tabulated and the angles of said groove 50 necessary for correction within two following leads may also be in per cents of the reciprocable with the tabulated and the true position oi the correcting 'member i may be iound by the aid of the scale 54. The position of groove 50 may be chosen that the rack ll is moved in the one, ,or in the other direction to increase or decrease the ratio as desired.

To get a helix lead of true size, the following conditions are to be maintained If Ws=stroke of carriage 2 Wz=efiective way of rack 43 =lead of the helix to be obtained Sw=lead of the helix next to the desired one and possible to be obtained with the change speed gears at hand then:

Ws:Wz=X:Sw

gives the values to difference of the values Ws and We may be given desired lead. The scale 54 would have to bear the proper markings. The change speed gears may be arranged at any other position in the gearing.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a. machine of the character described, the combination of a table, meansfor reciprocating it, a rotary work support on the table, selectively variable means for rotating the work support and means controlled by the table for altering the speed at which said selectively variable rotating means become effective upon the .work support. r

2. In a machine of the character described, the combination of a table, means for reciprocating it, a rotary work support on the table, selectively variable means for rotating it, an element movable relatively to the table and supported thereby, and means controlled by the element for altering the speed at which the said selectively variable means become effective upon the work support.'

3. In a machine oi! the character described, the combination of a table, means for reciprocating it. a rotary work support, selectively variable means for rotating the an element movable relatively to the table and same, means for imparting movement to-said element relatively to the table while the table is reciprocating, and means controlled by said element while in motion relatively to the table for altering the speed at which said selectively variable rotating 'means become eflective on the work support.

4. In a machine of the character described, the combination of atable, means for reciprocating it, a rotary work support, selectively variable means for rotating the work support on the table,

an element movable relatively to the table and reciprocable with the same, selectively adjustable means for imparting movement to said element relatively to the table while the table is reciprocating, said element actuating the selectively variable means for rotating the work support, whereby inaccordance with the movement of said element relatively to the table, the speed of said selectively variable means is altered.

work support on the table get a lead of true size. The i 5. In a machine or the character described, the combination of a table, means for reciprocating it. a rotary work support, selectively variable means for rotating the work support on the table, a rack bar supported by the table and in engagement with the selectively variable means for rotating the work support, and means 'for shifting said rack bar r latively to the table to a selectively determined in motion.

6. In a machine of the character described, the combination of a table, means for imparting reciprocating movement of uniform stroke to said table, a rotary work support on the table, selectively variable means for rotating the work support on the table, a rack bar carried by the table and selectively adjustable means for moving said rack bar relatively to the table while the latter is in motion for altering the speed of the work support rotating means from that speed which said selectively variable means would have when engaged by the rack bar fixed to the table.

7. In a machine 0! the character described, the combination of a table, a pressure fluid mechanism for reciprocating said table with a uniform stroke, a rotary work support on the table, selectively variable means for rotating the work support on the table, a rack bar carried by the table and in engagement with said selectively variable means and adapted to operate said selectively variable means upon reciprocation of said table, a lever carried by said table and connected with said rack bar, and means for rocking said lever during movement of said table to impart a relative movement to said rack bar with respect to said table.

.8. In a machine of the character described, the combination of a stationary base, a table, means for uniformly reciprocating said table on said stationary base, a rotary work support on the reciprocating table, selectively variable means for rotating the work support on the table, a rack bar slidably carriedon the table, a bell crank lever pivoted to said table and engaging said rack bar and an element on the stationary base for rocking said lever during movement of said table, whereby a relative movement is imparted to said rack bar with respect to said table.

9 In a machine of the character described, the combination of a stationary base, a table, pressure fluid mechanism for reciprocating the table at uniform stroke, a rotary work support carried by the table, a selectively variable set of change speed gears driving said work support, a rack bar mounted on the table for sliding movement, a bell crank lever pivoted to said table and in engagement with said rack bar, an angularly adjustable corrector element carried by the base and provided with a groove engaged by said lever to determine the rocking movement of said lever during the reciprocating movement of the table with respect to the base, said rack bar being in driving engagement with the selectively variable set of change'speed gears.

. ALFRED RICKENMANN.

degree while the table is 

